What brand of batteries are you using? There is no way to get an accurate SOC on an SI paired with lithium batteries without closed-loop comms nor is there a means to adjust voltage setpoints for generator start.
Every decision the SI makes is based on SOC. As far as I can tell, when selecting the battery type when commissioning the SI, it loads pre-determined setting (none of which are documented) that SMA has decided on and they can not be changed. So if you select FLA or VRLA and use lithium it will never work quite right. The only lithium batteries I have every used with a SI is Discover Energy lithium batteries and their Lynk 2. So my experience is limited in this regard but the combo works well for me. Lead-acid batteries also work great. The SI is a unique beast. Programming it is very different from other inverters from that time period. Lou Russo Owner [email protected] Office - 808 345 6762 Direct Line - 808 731 1907 Spree Solar Systems LLC CT-34322 On Fri, Sep 11, 2026 at 4:04 AM Jim Gowdy <[email protected]> wrote: > Good Morning, > I've integrated some lithium battery cells to a single Sunny Island > inverter (model SI4548-US-10) and I'm having an issue with the Sunny > Island's SOC. My batteries will be at pretty much full charge and the > inverter will show something like 50% SOC and it's causing me problems of > starting the generator prematurely and one time it shut the system down. I > am still looking through the manual, but I was wondering if there is a way > to calibrate the state of charge or use battery voltage for my setpoints. > I'm timid to call their tech support because these batteries are not on > their approved list. Any input would be appreciated. > > -- > Jim with Gowdy Electric > Cambria, Ca 93428 > business 805 927 2630 <(805)%20927-2630> > cell 805 975 5279 <(805)%20975-5279> > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/[email protected]/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org >
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